The old code was keeping the values of SRTT and MDEV (really RTTVAR)
scaled, as if they were multiplied by their alpha and beta (bravo) factors.
This will be a minor issue when we try to use TS for RTTM.

Also, we weren't scaling those values back, so if you looked at e.g.
/net/tcp/1/status, you'd get a scaled value for the RTT.